The invention concerns a circuit for controlling a brushless electric motor, especially a slow-running flat motor of the type appropriate for operating washing machines directly for example. In directly operating the drum of a washing machine the speed must be varied within extensive limits, specifically 40 to 70 rpm for the wash cycle and approximately 1000 rpm for the spin cycle. With synchronous motors this is completely impossible because the speed of a synchronous motor depends on the mains frequency, which is invariable.